An X-ray imaging technique called low-dose computed tomography (LDCT) can be used to detect lung cancers at an early and treatable stage in people at high risk for the disease, Canadian researchers have shown.
LDCT scanning takes 30 seconds and shows several hundred thin cross-sectional images of the lungs from top to bottom, whereas conventional X-rays show only two views of the chest.
Between June 2003 and December 2005, Toronto researchers enrolled 1,000 current and former smokers in an international study testing whether LDCT is suitable for the early diagnosis of lung cancer in people with no history of cancer who smoked at least one pack of cigarettes daily for 10 years.
The majority of the 20 lung cancers detected in these people were found in their early stages, says Dr. Heidi Roberts, a researcher in the department of medical imaging at Toronto General Hospital. “You have to keep in your mind that all these people are healthy. They come off the street with no symptoms whatsoever. They don’t know they have cancer.”
While there is now a large body of evidence suggesting lung cancer screening with LDCT can find cancer while it can still be cured, there are no high-quality studies demonstrating that screening actually reduces death rates. An ongoing U.S. trial involving more than 50,000 people is aiming to address that question.